Giáo trình sinh học đại cương phần thực vật ths nguyễn mỹ nhung

Mo phan sinh ngon cho ra 3 loai mo phan sinh sP cap: Mo phan sinh vd se cho 16p bieu bi, tien tiTOng tang tuong tang non hinh thanh mach trong tru trung tarn, mo phan sinh cP ban cho ra

Nguyen My Nhung

Gido Trinh

Phan Thufc • •Vat

-r •

Ldl DE TVA

Trirfrng Dai hoc Dan lap Cilu Long muon khing dinh la trung tam dao tao nguon nhan life co trinh do cao cho khu vile dong bang song Cdu Long de phuc vu cho cong cube cong nghiep ho a, hien dai hoa dat nutfc thi phai nang cao chat lifting dao tao toan dien Mot trong nhtfng yeu to trong yeu la doi ngu thay co, he thong cac giao trinh va trang thiet bi day hoc.Cung vdi cac nganh cac cap trong toan quoc dang day nhanh tien do xay difng va cung co vi the trong xu the hoi nhap, trifting Dai hoc Dan lap Cufu Long dan tifng bifdc hoan thien de dtiting dau vdi nhtfng thach thtfc do, gop phan dtfa nen giao due dai hoc Viet Nam dtfng vtfng, ngang tam khu vtfc va the gidi

Ke hoach xay dtfng ve mot Bo giao trinh stf dung cho cac giang vien lam tai lieu cti ban de giang day, cho sinh vien nghien ctfu tham khao hoc tap la nhu cau cap bach cua nha trtfdng

An pham nay la giao trinh Sinh Hoc Dai Gifting - Phan Thtfc Vat cua Khoa Khoa Hoc Cti Ban, Trtfcfng Dai hoc Dan lap Cuh Long, do ThS Nguybn My Nhung bien soan

Lanh dao triftfng Dai hoc Dan lap Ctfu Long tran trong nhtfng cong hien, dong gop cua Quy thay co mo’i giang cung nhtf cac thay cd can bo - giang vien cti htfu cua nha trtfcfng

ThS. Nguyen Cao Dat

trong nha trifdng.

Tran trong gidi thieu gido trinh nay den Quy thay co va cdc em sinh vien trirdng Dai hoc Dan lap Cutu Long ■

Vinh Long, thang 09 ndm 2009

Q. HIEU TRtfdNG

Chitcfng 1

TO CHLfC CO THE THUC VAT

Chu trinh song mot co the thifc vat bac cao co mach dien hinh bao gom: hat duWc hinh thanh trong vo qua cay bo me va khi gap dieu kien thuan Itfi thi se nay mam, tao cay non (hay cay nay mam th hat) Cay non Idn len, trd thanh cay trtfdng thanh, phat trien hoa, tao hat mhi va chet, nho' do hoan thanh chu ky sinh trUdng va phat trien hang nam Cac te bao rieng biet cua cay khong boat dong mot each doc lap ma gibng nhif

te bao dong vat, ditoc to chufc thanh mo

A MO THl/C VAT

Mb la nhom te bao tUJng til cung thUc hien mot chiic nang.ThUdng thi cac mb sdp xep vdi nhau thanh cau true goi la co quan ThUc vat co cac co quan co ban la: re, than, la, hoa, qua

va hat Su phan chia cac co quan nay lam tang tfnh phde tap von co cua cac hoat dong song

Mb thuc vat co the chia lam 2 loai: mb phan sinh va mb chuyen hoa (mb vmh vien)

Mb sb cap cua co the dau tien d thuc vat gom 4 loai: mb phan sinh, mb co ban, mb bi va mb mach Moi loai mb gom mot hay nhieu loai te bao dac biet va cung thuc hien nhiem vu dac biet

Mb thtf cap hinh thanh va phat trien trong qua trinh sinh triidng thuf cap ve sau cua cay va khbng phai tat ca cac cay deu

co mb thtf cap

I- MO PHAN SINH:

La mb dac biet ma te bao chi co nhiem vu phan cat de tao

ra cac te bao mdi Cac te bao sinh ra tit mb phan sinh sau

M6 phan sinh ngon

Hinh 1 - Scf do cau tao mot thifc vat bac cao cd mach

M6 dan truyenX -AjlLong hut] II-

LChoi ben

~Bieu bi L6ng

tAng tnfcrng, Idn len cd khi gap nhieu lan beta te bao da sinh ra

nd, cac te bao nay biet hda de dam nhan nhiem vu chuyen biet

va trd thanh mo vinh vidn Thong thadng cac te bao cua mo chuyen hda khdng phan chia ntfa

M6 phan sinh hien dien trong suot ddi song thUc vat vd do chung ludn phan cAt de tao ra te b&o mdi nen 1dm cho cay khdng ngifng Idn len, day Id ddc tinh phan bidt thifc vat vd dpng vat

Te bao cua mo phan sinh ndm trong mot vung dac biet goi

la vung phan sinh Cac te bao mo phan sinh cd kfch thifdc nhd, vach te bao mdng bdng cellulose, te bao chat dam dac, nhan to

va thuy the nhd, cac lap dudi dang tien lap

1) Mo phan sinh ngon, mo phan sinh stf cap:

N&m d dau ngon re, dau ngon than, te bao mo phan sinh ludn phan cdt lam cho cay dai ra, sit sinh trifdng nay diftfc goi

la sif sinh tnldng sef cap tao ra cP the dau tien cua thUc vat (hinh 1)

Mb phan sinh ngon

Mb c3n ban

Re cai

Mb dan truyen M6 phan

sinh b&n

Te bao mo phan sinh ngon c6 hinh da gidc, kfch thiTdc nho

va tifcfng doi dong deu, sap xep xen ke va kbit nhau, khong chifa khoang trong nao ca

Mo phan sinh ngon cho ra 3 loai mo phan sinh sP cap: Mo phan sinh vd se cho 16p bieu bi, tien tiTOng tang (tuong tang non) hinh thanh mach trong tru trung tarn, mo phan sinh cP ban cho ra mo cP ban cua vd

2) Mo phan sinh thtf cap - Ttfdng tang (Tang phat sinh):

Cd nhiem vu trong sif phat trien thtf cap de tao ra cP the thuf cap cua thPc vat M6 phan sinh thtf cap lam thanh vdng quanh than, rd va lam cho cay gia tang dufrng kmh (tang day).Sir sinh trirdng thtf cap khong xay ra trong tat ca thifc vat.M6 phan sinh thur cap gdm cd thiTPng tang libe-gd va thPOng tang vd

Te bao cua thPng tang cd hinh chu' nhat dep va lam thanh mot Idp te bao, phan cdt theo hPdng tiep tuyen ve ca hai ben tiTPng tang lan liTPt cho vao trong vd cho ra ngodi hai loai mo khdc nhau, mo dPPc thanh do tiTPng tang se sap xep thanh Idp

va thanh day dd nhan

*Titofng tang libe-gd: (tang phat sinh libe-gd) nam gida mb

go (xylem) va md libe (phloem), md nay se phan cat cho ra md

gd thuf cap d ben trong va md libe thuf cap ben ngoai ngay sat tiTPng tang

TifPng tang libe-gd tao hau het cP the thuf cap cua thhc vat

Do la md phan sinh hinh tru mdng cd trong re va than Thong thifbng tiiPng tang libe-gd difPc hinh thanh trong thifc vat co si/ phat trien thuf cap d nhtfng cay STD (hai la mam) va cay hat tran (tiing bach)

Mot each td’ng quat, tiTPng tang libe-gd tao ra hau het md go thd cap, md libe thuf cap dPPc tao ra it hPn va bi tach ra cimg

Idp vo trong suot sif tAng trirdrng Mo g6 thtfr cap thifcfng dtfOc biet nhif la g6.

Trong vung c6 khi hau on hda sir tao thanh g6 theo miia la ket qud cua sir sinh triT&ng hAng nSm Sif phdt trien thuf cap cua day 1& dieu ddng ngac nhien: cay" Tule" each day 2000 nSm

or Osaka - Mexico, c6 chu vi la 148 feet (45 meters) nhiTng chi cao 131 feet (40m) Cay Sequoia khong 16 6 BSc California co than cao 100m (328 foot tall) nhifng dirdng kmh 7m (23 feet).Tirqng tang libe-g6 thirdng tao ra go suot mua xuan va mua ha

- Mua xu&n: ngay thirdng am i/dt, titong tang libe-g6 tao go

to, vdeh te bao mong goi la g6 mua xuan go sdm chuyen biet cho sq d&n truyen

- Mua ha: ngay kho, g6 di/qc hinh thanh vdri te bao nhd,

vach te bao day dSc biet cho sir nang dd

Do sir khac nhau gitfa g6 miia xuan v& miia ha, go thirdng cho thay ranh gidi va hinh thanh nhOng vong goi la vdng tAng tnrdng (vdng hang n£m)

^TittXng tang vo (tang sinh ban, tang bi sinh)

Te bao mo phan sinh nay cd hinh tru, nMm trong Idp vo cua than va re Nd se hinh thanh Idp chu bi ben ngoai la Idp bao phu bao ve than va rd triTdng thanh, cac te bao nay edn duoc goi la te bao ban do thirdng diTdc tarn them chat suberin ben ngoai vach te bao (do la nhdng te bao hoa ban)

- Ldp chu bi bao gom: tiTOng tang vo (tang bi sinh), Idp vo va tang luc bi Ldp chu bi thay the ldp bieu bi bi bong ra suo’t qua trinh phdt trien thd cap

- Mo libe (phloem) thtf cap se cho ldp tirong tang vo (tang sinh ban mdi) sau khi ldp vo bi lot ra

Cac htfp chat y diftfc suf dung trong y hoc

tai thifcrng diltfc trich ra th trong vo cay

- 6 Dong phi, dan chuong nhai nhdnh

V , 'l' - , 7

co truyen va hien

- 6 Dong phi, dan chuong nhai nhdnh non cua cay Neem (sau dau) co nguon goc th An do, de ngan chan sau rhng, ngoai

ra cdc hop chat trong cay Neem con co tdc dung trong sh phong

trh sau benh cua vai loai con trung pha hoai mua mang

- Th the ky thuT XVI, dan dia phUotag Peru da sb dung cay Quinine de chha benh sot ret, va den nam 1930, dhcfc chat nay dhOc tach ra th cay Canh-ki-na va dhoc pho bien tren toan the gidi

- Hien nay, nhieu duoc chat dhoc trich ra th vo cay cd the dieu tri vai benh ung thh, nd cd tac dung ngan ngha te bao phan chia" loan dong phan"

Vi du: Vo cay thuy tung Thai Binh Duong Taxus bervifolia cd nhieu duoc chat va cdc duoc chat nay cung duoc tim thay b 7

lohi Taxus la kim khdc cd sU ket hop vdi nam tren cay

- Ldp da cua khoai tay lot ra la Idp ban: ban dung de dong nut chai rUOu nho den th vo cay xoai Dia Trung Hai, moi mhdi

nam lai thu hoach ldp ban mot lan

Tom lai sh phat trien thh cap cua cay :ung cap nhieu san

pham khac nhh cao su, chewinggum, nhha cay, bia carton, soi nhan tao, thdc an gia sue tong hop, vat lieu lam kern, 19% loai

cay cd go thh cap cho giay: Moi nam My san xuat 16,8 trieu m

gd va ngUdi dan My tieu thu hang nam 500 pounds = 226,8 Kg giay (500 x 0,4536kg) chha tinh den 250.000 tan giay Idian hn,

2 trieu tan giay bao va giay viet moi nam

3) Mo phan sinh chen:

M6 nay duoc tim thay d giha than chinh cua cac cay than cd

da trhdng thanh (3 tre, true ho Hda ban (Poaceae) mo nay nam

d dot cua than lam cho long dai ra va sh sinh trhdng nay dhOc

goi la sh sinh trhdng gian tiet

Mo phan sinh chen tao nen co cau cua cay tcf d dinh Nhd

mo n&y mA cd phAt trien nhanh chdng sau khi nd da bi cAt

4) Stf phan hoa cua mo phan sinh : (hinh 2)

Sir phan h6a cua mo phan sinh xay ra khi moi te bao phAt trien thanh dang chuyen hoa cudi cung Co the thay mot so bien doi xAy ra trong pha kdo dAi te bAo Do hap thu tham thau nude mA te bAo trifcmg len, thiTdng lAm te bAo keo dAi nhieu hem, ve sau cAc khong bAo nhd xuat hien trong te bAo chat dac se dung hap de tao khong bAo dem Idn chda dich bao 1A ndt dAc trifng cua te bAo trirdng thAnh Sir gian nd te bAo xAy ra ngay diTdi dinh chop hoAc dinh te bAo dang sinh trirdng lAm cho cAc vung nAy bien thAnh vung sinh trirdng ciTc dai Sir phan hoa chu yeu c6 Hen quan vdi quA trinh sinh trirdng cua vAch te bAo MAc du 1A phan khong song, nhimg vAch te bAo 1A tinh chat dAc tnmg nhat vA 1A ndt tieu bieu de thay cua te bAo thiTc vat Chung dirqc hinh thAnh nhd phan song cua te bAo goi 1A nguyen sinh chat, trong khi do te bAo van tAng ve klch thirdc vA chu yeu gdm cellulose, pectin vA glycoprotein Sir tong hop cellulose xay ra d gan mAng sinh chat, rdi cellulose lAng dong d ben ngoAi mAng diTdi dang mot mang liTdi gdm vd so sefi con Trong phan nen giffa cAc sqi con 1A protein vA glycoprotein dirqc l£ng dong lai CAc chat nAy dirge an vAo vAch nhd cAc chat tiet tir the Golgi cua te bAo thgc vat, rdi tui tiet dung hgp vdi mAng te bAo de bAi xuat cAc chat chtfa trong tui Gitfa vAch cua hai te bAo lan can 1A mot tang mdng gdm chat pectin ket dinh goi 1A phien giffa nham lien ket te bAo vdi nhau Phien giffa dirge hinh thAnh dau tien trong quA trinh phan chia cua te bAo phan sinh khi cAc tui tiet tff the Golgi di den vAch giffa hai

te bAo vA hgp lai Dong thdi phan con lai cua tui tiet thi dung hgp vdi nhau de tao mAng tren ca hai phia, nhd do tAch rieng hai the nguyen sinh mdi De tAch rieng cAc te bAo thgc vat trong phdng thi nghiem, ngffdi ta thffdng hoa tan phien giffa bAng cAch cho tieu ban ngap trong acid, do 1A quA trinh ngam

- Thu" hai la cd vung mdng d vach te bao canh nhau cho phep

cac sod te bao chat mdng manh di qua goi la sqi lien bao hay

cau sinh chat Cac vimg mdng diidc goi la Id (pit) va thifdng ton

tai thanh tilng cap (doi) ddi dien gitfa cac te bao lan can Hau nhif moi te bao deu cd vach sd cap lang dong trong qua trlnh

phat trien tif cac mo phan sinh Nhif la bo phan cua qua trinh phan hda, mot so te bao tiet them tang cellulose vao phia trong vdch so cap de hinh thanh vdch thtf cap Dieu nay la dung vdi

mo d&n truyen nude va mo nang dd nhifng khong xay ra trong cdc te bao dang boat dong trao doi chat Thudng thi cac vi sci

cellulose iMng dong thanh ba Idp chdng len nhau de tao mot mang lifdi nang dor vdng elide Pectin mem, dd uon cua chat

nen trong ca vach so cap va thu* cap cd the duOc thay ddi dan bang lignin Lignin cd tac dung lam vach te bao them vtlng

chdc, dong thdi cung lam cho vach te bao khong tham nude,

tham khi khien cho nguyen sinh chat ben trong khong the :.hu nhan chat dinh dudng va bi chet, de lai xoang chufa day dich

bao Vach thd cap khong hinh thanh trong cac vung Id, mac du ddi khi chung nhd ra thanh cac gb (nhif trong minh hoa), tao

nen cac Id vien (3 thtfc vat Hat tran - nhdm cay bao gdm cay

la kirn (cay loai tung bach) thi Id vien cd the cd cau true rat

phde tap Ket qua cua pha phan hda, nhieu loai te bao thifc vat

dirqc hinh thanh va mdi loai te bao diftfc chuyen hda de thtfc hien mot chile nSng rieng trong ddi song cua cay

Mo phan sinh ngon

—Mo phan sinh long

JjjrMo phan sinh benHinh 2 - So do vi tri cdc mo phan sinh trong cay

II- MO CHUYEN HOA:

Mo chuyen hoa la mo cau tao nen hau het khoi liiong ccf the thifc vat, lap day ben trong cua re, than, la, co nhiem vu dif tri?, nang dO va la nen tdng cua sir trao doi chat Mo chuyen hoa gom 3 loai mo: mo che chd, mo ccf ban, mb din truyen.1) Mo che chdr sof cap:

Nim b mat ngoai cdc ccf quan va bao phu khip ccf the there vat Co cau tao sef cap, nhiem vu cua mb nay bao ve, trao doi,

va tiet Thanh phan cau tao cua mb che chbr gom:

a) Bieu bi:

Gom mpt Idp te bao co hinh dang va kich thiTdc thay doi tiiy loai Cdc te bao thiTcfng det, xep khit vao nhau khbng chiTa khoang trong nao ca Vach te bao bieu bi bing cellulose day d mat ngoai va mbng d mat trong, nhef vach te bao bieu bi day b mat ngoai cung giup cho giam bdt sir mat mrdc cua cay qua be mat Idp bieu bi Mot so cay song trong vung qua khb co the co bieu bi nhieu Idp de trdnh sir mat niTdc

b) Cutin:

Ben ngoai bieu bi diTOc bao phu bdi Idp cutin la Idp diTOc hinh thanh tir te bao bieu bi Ldp cutin khbng tham mrdc va khi nen sir bao phu cutin giup giu’ nirdc ben trong cay, ngan can sir hut am va sir mat mrdc Ben ngoai Idp cutin co khi co lefp sap mau tring, trefn, lang

1 Long don bao d la tao ta; 2 Long don bao d cay vau;

3 Long da bao 1 day d cay cue tim; 4 Long da bao hinh

chum d cay sdi; 5 Long da bao hinh sao d la nhdt;

6 Long da bao phan nhanh d cay cha node

Hinh 3a - Mot so dang long che chd

- Ben canh te bao bao ve la te b&o k6m (guard cell)

- Khoang trong ben dirdi 16 khi la phong difdi 16 khi

Te' bao kem cung giup dieu khien sit dong md cua 16 khi, trao do’i khi va nifdc

Hcfn niTa 16 khi giup dieu chinh lifpng khi cacbonic khue'ch tdn vao trong Id, can cho sif quang tong hop va lirpng nirdc boc hori td la

6 mdt dirdi cua Id co nhieu 16 khi

Vi du: La soi, mdt dirdi cua Id: 1 cm2 co khoang hern 100.000

16 khi, 16 khi giup cay gid nirdc nen thich hop cho defi song thiTc vat chuyen tir nirdc len dat lien

6^

d) Long che char (Hinh 3a):

Trong Idp te' bao bieu bi, mot so te' bao moc dai ra tao thanh long, long co nhiem vu va hinh dang khac nhau va cung co vi tri khdc nhau tren cay Cac loai long va nhiem vu:

- Hau het ben ngoai cua la (b£ mat) than non co nhieu long che chd Cac long nay giup cho cay giam bdt sir thoat hoi node qua be mat la hay than

- Long co dang moc co the dam xien qua con vat an moi

- Long ngtfa (long cua cay tam ma) co dau tron, khi bi gay co the dam xuyen vao thu an co va phong chat doc vao vet thiTOng

- Long co the tie't ra chat tie't

Vi du: Long d la rau can day la.

- Long cua cay bat moi (venus's flytrap - bat ruoi) tie't enzim

de tieu hoa con moi

- Long re la nhtfng long n£m gan dau rd co nhiem vu hap thu node va muo'i khoang td dat

Nhieu long tie't cd gia tri kinh te' quan trong

Vi du: Menthol la chat tif hat tieu, la bac ha, sqi bong la

nhtfng long tif bieu bi cua hat bong vai, thuo'c la, thuo'c ngu resin tinh chat trich tif long cua cay cannabis

Cda trade Khoang khi

Cda sauz

Hat lap luc

Nhu mo dSc Nhu mo dao

Nhu mo khuyet Giao mo goc

3.

1

r 2

EXXI

2) Mo cor ban: (hinh 4)

Hau het te bao mo co ban dcfn gian va thiTcrng chi gom mot loai te bao, gdm 3 loai chinh la nhu mo, giao mo va ciTcrng mo

a) Nhu mo:

Hien dien d hau het cac phan cua cay nhuf hoa, trdi, re, than, la Khi tnrdng thanh te bao nhu mo la te bao song co the phan chia, vach te bao mdng bang cellulose (diftfc nhuom mau hong sau khi nhuom 2 mau son phen luc iod) Te bao co nhieu hinh dang: hinh da giac, hinh nhieu canh gan tron, sap xep kbit nhau hay chifa cac khoang trong.

Te bao nhu mo co kha nang phan chia hoac biet hoa, dieu nay cho phep te bao cd nhiem vu dac biet lam thay doi tinh trang cua cay

Soi citcfng mo

Hinh 4 - Mo phan sinh va mot so' mo chuyen hod

liar1

Nhu mo c6 the phan chia:

* Theo nguon gd'c:

- Nhu mo so cap dooc sinh ra t£r mo phan sinh so cap, nhu

mo thdr cap co nguon gdc tif mo phan sinh thtf cap

* Theo hinh dang'

+ Nhu mo d&c: te bao cd hinh da giac va sdp xep khit nhau.+ Nhu mo dao: te bao cd hinh nhieu canh gan trdn va sdp xep chifa cac khoang trong nhd goi la dao

+ Nhu mo khuyet: cd nhiing khoang trong to hon

* Theo nhiem vu:

+ Du tru": nhu mo nay thodng cd d re than Chat do tri? cd the la cac carbohydrat (trong khoai tay, hot ngu cdc, hot ca phe), tinh dau , mudi, cdc sdc to va acid httu co (acid citric cd trong te bao nhu mo d vd cam, chanh)

+ Dong hoa: te bao nhu mo cd nhiem vu dong hda cd chiia luc lap ben trong, nhu mo cd luc lap duOc goi la luc mo Luc mo thudng gap d co quan cd mau xanh cua cay, nhat la Id va than non Cd 2 loai luc mo:

- Luc mo hinh hang rao: te bao dai, hep, sdp xep khit nhau

- Luc mo xdp: te bao cd nhieu hinh dang va sap xep thua.Ngoai ra nhu mo con cd nhiem vu trong sir ho hap te bao, tong hop protein, chodn chd trong Te bao nhu mo daqc cay tao

ra de lam lanh cdc vet thuOng hodc lam cho cay thich hop vdi dieu kien moi tnrdng

b) Md nang d&:

La md gdm nhiing te bao cd vdch day, viing chac, dam nhiem chile nang co hoc cua cay la: giup cay nang d3 va dilng vting Cdc te bao cua md nay cd the dai hay ngan va vdch te bao day nhd tarn mdc to' (lignin) hay cellulose

Thtfdng phan biet 2 loai :

*Giao md (Mo day, Hau moj Hinh 5 :

¥ irN

Hinh 5 - Cac loai mo day

A Mo day phien; B Mo day gdc; C Mo day xop (de y cdc

khoang gian bao)

Thadng xuat hien trong nhffng soi hoSc trong nhang tru, nang dd nhdng phan non cua than cay ma khong ngSn can sd phat trien cua than non, cung nhif sif hinh thanh cua Id

Te bao cua giao mo la te bao song, thi/dng keo dai ra va hai dau nhon, no duWc biet hoa tif nhu mo Vach te bao giao mo la vach thtf cap day bdng cellulose, be day cua tat ca cac vdch khong dong deu nhau, vi la te bao song nen te bao tang tru’dng

vd keo ddi ra

Giao mo difcfc phan biet cac loai do sir day len cua cellulose trong vach te bao

+ Giao mo goc: cellulose chi day len d gdc te bao

+ Giao md tron: cellulose day d khap tat ca cac vach te bao.+ Giao md phien: cellulose day d vach ngoai va vach trong cua te bao, lam cho te bao nhif sap xep thanh Idp

*Ci£(mg md (Md cdng - Hinh 6)

THU

Te bao da keo dai d cuong qua leNhom te bao da o thit qua di

Te bao da phan nhanh d la ch& Te bao da hinh sao d cuong Id trang

Hinh 6 - Mot vdi dang te bdo dd

La nhtfng te bao co vach thu' cap day do tam lignin hay moc

to, xuat hien trong than nhir la bo khung cua cay co nhiem vu nang dcJ cho cay

Te bao citcfng mo khi trifdng thanh co vach thtf cap rat day

va doi khi chiem gan het xoang te bao, chat nguyen sinh giam thieu nhat la te bao khong keo dai ra ditoc nffa Thtfbng te bao chet di khi trifdng thanh

Hai loai cifcfng mo difcrc hinh thanh tif nhu mo la: te bao da

va scri

+ Te bao da: co nhieu hinh dang va xuat hien don doc hay thanh nhom nhd Nhitag nhom nhd cua te bao lam thanh hat ben ngoai: qua le, doi khi te bao da lam thanh Idp cdng nhtf la

vd cu lac (dau phong)

y • " *

+ Te bao scfi: la nhffng te bao keo dai co chieu dai thay doi

td vai milimet den v4i trSm milimet Nhieu scd ciftfng mo diftfc

sd dung de det vai, hien nay ngirdi ta nubi cay htfn 40 ho thifc vat cho scfi CAch nay 8000 nSm, con ngUdi da biet sd dung stfi

de det vai

Stfi cua Agave sisalana (stfi sizan, sisan) diftfc dung lam chdi, b£n chai vd day ben Vdi lanh dtftfc 1dm td sdi cua cay lanh

Linum vsitatissimum Cannabis sativa, nguon cua"marijuana"

cung cap sgi lam day ben va day thdng

3) Mo mach - Mo dan truyen (Vascular tissues - hinh 7):

La mo dac biet cua thifc vat co mach, giup cay song duoc tren moi trifdng dat lien Mo gdm nhdng te bao co dang hinh 6ng rd ng, din truyen nifdc, thdc dn va cac chat di den tat ca cac phan khac cua cay

Hai loai mo mach xuat hien trong cay la: mo go va mb libe Mbi loai diftfc hinh thanh sudt trong ca su” sinh trifbng so cap

va sinh trifbng thd cap

gd (xylem)

La mot he thdng gdm cac te bao xep nbi tiep nhau thanh hinh dng rdng van chuyen nifdc va cac chat hba tan td re di khap tat ca cac phan cua cay

Co 2 loai te bao van chuyen trong mb go:

1 Quan bao xoSn; 2 Quan bao thang; 3 Quan bao num.

+ Quan bao (tracheid - Hinh 8):

La te b4o dan truyen dSc biet nhat, dai, hep va hai dau nhon, xep noi tiep nhau te bao nAy v& te b&o khdc, vdch thuf cap tam lignin day Nirdc di chuyen tif quan bao nay sang quan bao kia xuyen qua vung vdch te b&o mong hay cdc 16 thung.+ Thanh phan mach - mach go:

La nhtfng te bao dac biet tuy thuoc vao quan bao, do la nhtfng te bao ngan, rong, te bao co hinh dang tru va xep nd'i tiep nhau Vach ngan ngang te bao thifdng tan di va hinh thanh nhtfng ong tron giiip sif van chuyen nutfc hieu qua

Quan bao va mach go c6 vdch thuf cap day tam lignin va la

te bao chet khi trilorng thanh Khong cd vach te bao ddy, quan bao la thanh phan mach cd the meo md, cong o&n do life hut,

dp life cua nildc day trdn xuyen qua thifc vat d ben dildi

+ Nhu md gd:

Chung quanh quan bao va mach gd con cd cdc te bao nhu md

gd, vdeh te bao cd the tam mdc to hay con cellulose

Do vdeh te bdo day, nen ngoai nhi§m vu ddn truyen md gd con cd nhiem vu nang dd giup cay ddng vtfng

*Afd libe (phloem)

Van chuyen nifdc va cac chat dinh dirdng, chat hba tan (difdng) di khdp cay Khac vdi md gd van chuyen mrdc di len b&ng ap life am, md libe van chuyen cac hop chat di xud'ng nhd life hut Te bao cua md libe con song khi trtfdng thanh

Thanh phan cau tao cua md libe gom:

+ Te bao ray (te bdo sang):

Ld te bao dan truyen chfnh trong md libe, do la nhttng te bao dai, nhon va gdi len nhau d cudi, vach ngdn ngang con thung nhtfng lo nhd goi la lo ray, cay hat tran, lo ray cd khdp tat ca cdc vach cua te bao ray

(3 cay hat kin, te bao ray la nhQng te bao ngdn, rdng hern va sdp xep nhau thanh mot dng dai (dng ray, dng sang) Tren vach ngdn ngang hinh thanh vung goi la tam ray mang cac 16 ray To’ chile nay (tam sang) cho phep sif van chuyen cdc chat dinh diTdng nhanh hieu qua

Te bdo dng ray trifdng thanh khdng cd nhan nhifng vdn con chat te bao Mdi te bao dng ray diTOc ndi tiep vdi mot hay nhieu hon te bao kem xuyen qua cdc sqi lien bao Chinh nhd te bao kem giup te bao dng ray van song va boat dong du thieu nhan

+ Te bao kem la loai te bao nhu mo co nhan to, co ty the, the golgi, lap the, khong bao Vdch te bao bi thung nhieu 16 vdi

vd so stfi lien bao xuyen qua Te bao k6m tham gia dieu hoa boat dong trao doi cua ong ray

B CCf QUAN DINH DUONG CUA THUC VAT.

Co quan dinh difdng cua thifc vat bao gom cac loai mo khac nhau: Mo phan sinh, mo bi (mo che chd), mo co ban va mo dan truyen Thifc vat rat thay do’i ve hinh thai (co quan dinh dodng)

va chu ky dbi song de thich nghi dSc biet vdi moi trtfcfng

Vi du: Cay xiTOng rong hinh kim, day nho canh la xum xue,

cay hodng doong long 16y ma trong do co vai tro dac biet do so sdp xep khac nhau cua mo thifc vat

Cay co the song mot nam: goi la cay nhat nien (cay hang nien)

Cay song nhieu nSm diTOc goi la cay lifu nien (cay nhieu nSm, cay quanh nSm)

I- Rfi (Hinh 9):

Re la co quan dinh dOOng moc diTdi dat cua cay, gift chat cay vao dat, hap thu, van chuyen va do trtf node cung chat dinh dodng cho cay Ngoai ra re con hap thu oxi trong dat

1) Cac kieu re:

a) Re tru, re edi, re chinh:

Re dau tien 16 ra ttf hat la true ha diep se phu to thanh goc

re, rd cai tir mam to, hinh thanh phan Idn re va hien dien suo't ddi song cua thifc vat Re chinh phdt trien nhanh va dam sau vao dat co the dai den 53m, gia tdng sd nang do va cho phep thiTc vat sd dung cdc chat ben trong long dat

Rd chinh phan nhdnh va cho ra cac rd ben (re phu, rd thtf cap) moc xidn hay ngang Rd phu nho hon rd chinh va rd phu

co the phan nhanh thdnh rd cap 2, cap 3

Pinus Silvestris

Re ban

<

Re ciia Lan(Treniophyllum)

Hinh 9 - Cac loai re

b thong re sqri (a fibrous root system) - re chum:

Re chfnh bi hoai di tif trong mam hay co ddi song ngdn, tif

than se hinh thanh he thong re scfi dang chum Cdc re stfi co

Rich thifdc nhd tifcfng dtTcfng nhau, thitffng moc can nhifng phat

trien rong Chung hap thu nhanh chong nhtfng chat n&m gan

m^t dat va ng£n chan sif bao mon, hau het r§ nhom cay dcfn tCf

diep deu cd he thong rd stfi

c Re bat dinh (adventitious roots)

Moc tCr cdc mat cua than bd, than ngam, than khf sinh, hoac moc tCr cac ke rang cua la trtfcrng sinh (KalanKoe) Thacfng re bat dinh cung la he thong r§ stfi

2) Cac phan ciia re:

TlT dirdi len tren re gom c6 cac phan :

* Chop r^:

Nam tan cung d dau re, co cau tao giong cai bao deo vao ngon tay, bao phu dau r§ va bao ve te bao ncri do Re phat trien nhanh chong, moi ngay co the mat khoang 10.000 t§ bao do chung xuyen qua dat Mo phan sinh chop rd day te bao di xa hcfn ve phia trade lam te bao nay vdcfn ra ngoai rd

Chop rd cung tao ra dich nhay, Id chat nhqa bao vd dau rd khoi kho, no cung giup bdi trefn dau re de’ rd phat trid’n nhanh hern khi di vao dat Dich nhay con giup vide hap thu nitdc va chat dinh dirdng trong dat

* Vung ph&n sinh :

Ndm ngay phia sau chop rd, cac te bao cua vung nay phan cat nhanh chong cho ra cac te bao mdi

* Vung tang tritdng:

Te bao trong vung nay keo dai ra do sir gap khuc lai de re xuyen qua dat nhanh chong Vung nay chi day vd lang

* Vung long hut - Vung triidng thanh:

Trong vung nay, te bao trabng thanh bidt hda (vung chin- mature) vd la vung cung cd nhieu re nhd nhd ra td Idp te bao bid’u bi O thifc vat, long hut rat phong phu co khi co den vdi ti long tren rd Chinh nhd long hut 1dm tang didn tich be mat hap thu cua rd

dufrng kinh va sau cung tiep gidp vdi than d co re,

3) Cau tao cua re:

Trong cau tao re non STD (song ttt diep) hay DTD (don td

diep) thu'dng khong khac biet nhieu Mot lat cdt ngang qua re con non, td ngoai vao trong thifbng phan biet 2 vung:

a) Vung vo:

- Ben ngoai ciing la bieu bi bao phu hoan loan re trd d chdp

re, thudng khong co Idp cutin b£n ngoai bieu bi vd dieu nay thfch hop cho viec hap thu node va mudi khodng qua vach te

bao rl Bieu bi cua re khong co 16 khi

- Nhu mo dq trff hinh thanh mot he thong mo co nhiem vu

to Idn trong sit chon loc de re hap thu (node, muoi khodng) di chuyen qua Idp bieu bi va dong thdi dif trtf chat dinh difdng cho sif phdt trien cua cay sau nay

- Noi bi la Idp te bdo nhu mo, xep kbit nhau va nam thanh vong ben trong cung cua vung vo Vdch te bao noi bi cd mot khung d&c biet tam suberin hay moc to lam thanh dai (khung) caspary khong tham nifdc

Do sir s&p xep cua khung caspary, noi bi cd the thich nghi vdi viec van chuyen cua chat dinh difdng va node thirdng xuyen, dirqc thuc hien bdi mo dan truyen trong tru irung tam cua re

b) Tru trung tam:

- Tru bi (chu luan, vo tru) la Idp te bao nhu mo ndm ngay ben dudi noi bi, noi day se phdt re nhanh hay re con do te bao

1) Hinh thai cua than:

Than la ccf quan dinh difdng thtfcfng khi sinh Ndi ehung than

ditoc phan biet do moi trtf&ng song: trong khong khi (than khi

sinh), trong mfdc (than thuy sinh) hay trong dat (dia thifc vat)

Than khi sinh thtfdng diftfc chia l&m 2 loai chinh: than g6

thacrng cdng, rSn ch£c, va than cd co than mem thifdng chda

nhieu nu’dc Than thufrng diftfc phan biet trong 2 nhdm chinh:

* Th&n DTD (dan til diep):

Thadng la than cd cua cay nhat nien, cay ngu coc (lua, bdp),

mia, tre, true hofic cdc cay lan, hue Cay than g6: difa, cau

mang chum Id dr ngon cung la cay DTD

Hau het cay DTD khong cd sinh trtfdmg thuf cap

* Thdn STD (song tit diep):

Cd ca than cd vd than gd Cay than cd la cay nhat nien nhu

cac cay hoa mau: dau, cai hay mot so cay than cd da nien khde

phdt trien se phd vd Idp ndi bi xuyen qua nhu md vd, bieu bi va vao dat

- Md dan truyen ndm ben trong tru bi, bd go xep luan phien vdri bd libe lam thdnh mot vdng Bd gd cd sut chuyen hda hildng tarn cd nghia Id mach tien mdc xudt hien trade ndm ngoai, mach hau mdc xuat hien sau va ndm trong

Trong cimg la nhu md tuy, nhifng cd khi bi mach go phdt trien lan dp

Re hap thu ntfdc, mudi khodng tif dat va van chuyen di len trong md gd Trdi lai rd nhan cac chat hOu cd tir tren Id di xudng theo dadng van chuyen trong md libe Thong thadng cac chat dinh difdng nay diftfc dq tri? trong te bao nhu md vd de sif dung ve sau

II- THAN:

Hau het cdc cay than g6 STD deu da nien, tat ca cdc bo

triforng thd cap

2) Cac thanh phan cua than:

Than thi/dng co dang true thing dufng, tren than co:

- Long (dot) la phan than nim gitta 2 mdt

va dnoc goi la choi ngu

- Choi ngon n&m d dau ngon than

Thong thifdng, than dai ra d vung long, vai loai thifc vat

va Id dirdng nhif mpc chdng len nhau

Mot lat cdt ngang cua than thifdng dtftfc phan biet:

a) Vung vd (hinh 10b):

- Bieu bi bao chung quanh than, gdm mot Idp te bao giong

ngoai cd the co long che chd

+ Nhu mo chiem hau het vung vd Vai te bao nhu mo vd nam phia ngoai cd chda luc lap tham gia vao qua trinh va cd khi dir trtf tinh bot

- Tang sinh bot la Idp te bao nhu mo gidi han ben trong ciing cua vung vo, cung c6 khi co dai caspary.

b) Tru trung tam: (hinh 11)

- Ngay diXdi tang sinh bot la vai Idp te b&o tru bi cung la nhtfng te bao nhu mo nhi/ng khi hcfi gia, tru bi thufrng tam moc to'

Trong than, mo dan truyen nSm trong cdc mach va phan nhdnh de di vao la Trong b6 mach gom co: bo libe d£n truyen cac chat dinh difdng n&m d m&t ngoai cua bo, bo gd dan truyen nifdc n^m ben trong cua bo Bo go co sir chuyen hoa ly tam vdi mach tien moc nhd xuat hien trifdc n&m ben trong, mach hau moc to xuat hien sau n&m ben ngo&i Thirdng scri ciTOng mo dai, c6 vdch day pho'i hop vdi mach dan, co khi lam thanh bao, bao quanh cac bo mach

Cdc bo mach sdp xep khdc nhau trong cdc loai cay khac nhau O cay DTD cac bo mach s£p xep thanh nhieu vong va phan tdn trong nhu mo cua tru trung tam, cdn cay STD chi co mot vbng bo mach

Mo co ban dir trtf trong trung tam cua than la tuy

O tat ca cdc cay STD va thong , co vung te bao phan sinh nSm gitfa mo go v& mo libe, khi than sinh trirdng thtf cap, Idrp

te bao phan sinh do boat dong cho ra mo dan truyen thu* cap.4) Stf sinh trxfdng thtf cap ciia cay STD:

Khong phai tat ca thiTc vat deu co sir sinh trirdng thd cap, mot so cay than cd STD cd tang phat sinh nhiTng khong bao gid boat dong Nhitag nhieu cay than cd cung nhiT hau het cay than go deu cd sir sinh trirdng thtf cap do sir boat dong cua tang phat sinh va ket qua cua boat dong ndy la lam cho than cung nhiT rd t£ng ddy hay gia t&ng dirdng kinh

fTi’y-r

D

Ei

F

4?

AB

te bao co dai caspary

^Ayo trusC^Srbd libe

S&SX-bo go

9 15

-7 I"5 -8

I- Hinh cat doc; II - Hinh c£t ngang Cac mile do tif A tdi G

1 Mo phan sinh ngon; 2 Cac mam la; 3 Vong mo phan sinh; 4 Root; 5 Tang triidc phat sinh; 6 Vo so cap; 7 Libe so cap; 8 G6 so cap; 9 Tang sinh tru; 10 Bieu bi; 11 Vo tru; 12 V6 trong; 13 Libe thd cap; 14 Go thu* cap; 15 Mo mem vd; 16

Mo day

713 9, 8 4 1112 1514

I

Ccr cau thtf cap cua than va re khong khac nhau nhieu, nhifng vin cd the phan biet diftfc nhd v&o vi tri cung nhtf sif chuyen hda cdc bo libe gd so lap khdc nhau trong co quan.

a) Tii^ng tang vo - Tang sinh ban.

Te bao cua tang ph At sinh nAy phan cAt cho ra Idp ban dr phfa ngoAi va Idp luc bi hay nhu bi la loai nhu mo thuf cap ben trong, ca viing nay goi chung 1A chu bi Chinh Idp vd ban nAy lAm nhiem vu bAo ve cho cay, day 1A nhtfng te bAo chet do vAch

te bAo hoAn toAn tam suberin, Idp nAy lAm thAnh Idp vd ngoAi

vA Idp bieu bi cung nhd vung vd dan dan bi bong ra khi sir tAng trodrng van tiep tuc

b) Tang phat sinh libe gd (Tityng tang libe-gd):

Khi tang phAt sinh libe gd boat dong, libe thd cap difqc tao

ra se day libe so cap ra ngoAi vA gd thd cap day gd so cap vAo ben trong

O than cay cd sif tAng trirdrng thd cap, thd ttf cAc mo td ngoAi vAo trong: chu bi, vd, libe so cap, tang phAt sinh libe gd,

go thd cap, gd so cap vA tuy

O than cay gd phan Idn 1A gd thd cap O cAc cay nAy trong

nAm dau tien, co cau khong khAc biet vdi nhdng cay than cd,

mo dan truyen so cap cd the sAp xep lien tuc thAnh mot vdng nhifng cung sAp xep thAnh tdng bd red rac cung tren mot vdng Khi cay cd sd sinh tnfdng thd cap, cAc bd thifcrng sdp xep lien tuc vA nhif vay, tang phAt sinh libe gd cung lAm thAnh mot vdng lien tuc quanh than CAc te bAo gd difOc tao ra sdm trong mua tAng tnfdng cd kich thifd’c Idn hon cAc te bAo difOc tao ra vAo cuoi mua tAng tnfdtag, vA thifAng ngifdi ta chia:

- Gd sdm vAo mua xuan to vi cd nhieu chat dinh difdng vA cd nhieu mfde

- Gd muon vAo cudi mua he cd kich thifdc nhd

Tru gitfa <

Hinh 11 - Cau tao scf cap cua than cay hai la mam (hinh cat ngang)

Thifcfng mo libe thtt cap lam thanh Idp vo trong (inner bark)

cua cay

bieu bi d&y

—mo mem vo

vo trong (chiia tinh bot)

^~~vb tru i.libe scf cap r-tang trifdc phat sinh

go scf cap

mo mem ruot

Chmh sir khdc biet ve kich thirdc cua te bao tao nen cdc

vong hang n^m xep dong tam Dem cdc vong nay c6 the udc

liTOng tuoi cua cay Dieu nay quan trong trong khao co hoc

d cdc cay gia, do co nhieu thay doi ve cdc d&c tinh ly ho a

hoc xay ra trong cay nhat 1& trong mo go do d6, cac vong go gia

hon nSm d trong cung cua than co cdc te bao nhu mb se chet

di, nhiem vu dan truyen cua gb khbng con ntta, thay vao do la

nhiem vu chong dd cho cay, va luc do phan nay dtfOc goi la loi

(heart wood) cua cay, phan phia ngoai con boat dong diftfc goi

la dac (sapwood)

Trong co cau hau lap cua cay, mb libe khbng bao gib day

b&ng cac Idp go vi te bao cua mb libe thu" cap duoc tao ra it hon

so vdi gb thuf cap Hon nffa, vach te bao cua mb libe so cap hay

thtf cap deu la vach te bao mbng b&ng cellulose, nen te bbo cua

mb libe bi te bbo cua mb gb chbn bp khi cbc te bbo nay Idn ien

Do do, cac vong tbng trubng hbng nam cua libe thirbng khbng the dem diTOc, co khi khbng thay duoc Khbc vdi mb go, mb libe

lubn boat dong sudt dbi song cua cay, nghla la cay con song lb

mb libe vbn con lubn boat dong rat tfch cifc vb quan trong

Vo so cap <

Nhffng cay gia, thtfcfng khong con Idp bieu bi cung nhif Idp nhu mo vd, thay veto d6 1& Idp ban hay Idp vd ngo&i (outer bark) che chdr vik bao ve cho cay Ke do 1A Idp vd trong mdng, chinh

la Idp mo libe, phan cdn lai hau het 1& gd thuf cap

Ill- LA:

La co quan quang hop cua hau het cac cay Hinh dang, kfch thifdc cua Id bien thien tuy theo moi tri/dng md cay song

Ld cua nhtfng cay co nhiet ddi the dai 65feet (20m), trdi lai

la cua cay Wolffia (there vat thuy sinh) khong dai hon dau dinh ghim Cay" eim" trifdng thanh (chau My) cho vai trieu la, trdi lai cay Welwitschia mirabilis d sa mac chi cd 2 la trong sudt defi song cua nd

1) Hinh dang la:

Ld cd nhieu hinh dang, khong bao gid cd 2 loai cay cd Id gidng het nhau NgOcfi ta phan loai Id theo hinh dang cua day

la cung nho sdp xep cua Id tren than

Ld dirqc chia 1dm:

a) La defn:

Thirdng Id det, phdng, mdi cudng la chi mang mot la, cd khi

la khong phan chia phien Id vd cudng Id (hinh 15)

Ld co the xep tren than theo nhtfng kieu khac nhau de nhan dnh sdng tdi da va mat nifdc toi thieu Cach sdp xep cua Id tren than goi la diep ttf Ld moc theo cdc each :

+ Moc edeh: khi co mot Id tren mot mdt, Id co the moc luan

phien hay xodn oc

+ Moc doi: khi co hai Id tren mot mdt va moc ddi dien

nhau

+ Moc vong: khi co hefn ba la tren mot mat

Ld co doi song gidi han, thittmg chi co mot mua.

Tr£n Id cd gdn Id, cd nhi&u dang:

+ Gan la song song gdp d nhieu Id DTD.

+ Gan la hinh long chim, hinh mang lifdri, hinh chan vit

gap d hau het cdc Id STD

2) Cau tao cua phien la:

Hau het Id bao gom phien Id det, phang, va phan cuong Id mang no Tif ngoai vao trong cua mot phien la cdt ngang ta co:Bieu bi bao phu khap Id, co khi bieu bi co day long, tren bieu

bi co 16 khi khau (hon 11 trieu 16 khi d Id cai bdp) va mdt dildi

la co nhieu 16 khi hon

Thtfc vat sd dung 16 khi de trao doi khi, nhifng thifc vat cung mat mot so' liitfng Idn nude qua 16 khi trong sU thodt hoi nitfe.M6 ddn truyen trong Id ndm d gan la, vhi mo go nam tren

va mo libe ndm ditfi Ket thuc cua gan Id d phan cuo'i va nho

cua gan la hba vao nhu mo cua diep nhuc, noi ndhc va chat hda tan di chuyen ra vao gan la

Diep nhuc (thit Id) diTOc tao thanh te bao luc mo chda luc lap tao dufrng qua sif quang to’ng hop

a) La ndm ngang: co 2 loqi luc mo:

- Luc mo hinh hang rao: nSm d mat tren cua la, d£c biet cho viec hap thu dnh sang de quang tong hop

- Luc mo xop n&m ben difdi luc mo hinh hang rao, te bao co hinh dang khong dong deu, ng£n cdch nhau do nhtfng khoang gian bao Nhtfng te bao nay dSc biet cho sir trao doi khi cd khi con diTtfc goi la thong khi

b) La mpc thdng ditng: chi co mot loai luc mo co cimg

hinh dang

Str rung la la tien trinh binh thirdng Cay rung la hang nam vao cuoi mua sinh trirdng Cay co Id xanh quanh ndm cung co rung la mot It tifng luc mpt

Ld phan Ong lai vdi tin hi^u cua moi trirdng nhir la: ngdy ng&n hodc nhi^t dp qua lanh bdng sir rung Id, tren phien la hinh thdnh mot Idp ngdn cdch d vung gay rung ncri ddy cua cuong Id, ngdn cdch Id chet tiT than Ket qua la: gid, mira, hodc mot vai lay dong khdc lam rdi khdi than

ChUcfng 2

hot vung tarn suberin

vung long hut vung tAng trtfdng chop re

He thongCac phan cua re

re chiim

Hinh 12 - Mot so dang re d STD va DTD

•; — 16 ng

re bat dinh (khong do re mam tao ra)

// 're con

re chfnh

Thtfc vat bien doi hinh thdi va cP cau de thich nghi vdi ode

yeu to moi trirdng, noi thifc vat sinh song, hay tuy theo nhiem

Hinh 13a Phe cSn 6 Dutfc Hinh 13b Re khi sinh 6 LanCay chum gcri va Lan la 2 ho thifc vat co re moc va phat trien trong khong khi.

(j Difdc, cay co moc th than, canh toa xuong chung quanh goc than (r£ chan nom) giup cay dhng vtfng va la bo re tieu bieu trong moi trifcfng ngap mhn thieu oxi

d cAc cay: difdc Rhizophora, ban (Sonneratia), mam (Avicennra) c6 nhhng re mpc ngitoc th dhdi dat 1q ra ngohi khong khi vh dhhc goi Ih phe cSn (pnuemotophore), c6 nhiem

vu trao doi khi cho ho hap hieu khi Cdc re nay moc thing ra ngoai anh sdng, tren re cd mot vung vd chha mo khi (aeranchyma) xuyen suot trong vd, khi thuy trieu xuong oxi khuech tan th khong khi di vao trong rl bi chon sau trong bun.Nhhng cay song trong nifdc, dhc biet la nhhng cay song chim, khong chiu mat nhdc do sh thoat hoi nude, do do yeu cau

ve nhde khong quan trong nha Vi the co cau cua re rat don gian, vdi mo din truyen kem phat trien, mo gd khong ngam moc to

2) Re cay song trong khong khi (hinh 13a & 13b):

not re

Vi du:

3) Re dtf trff:

Re dtf trff thtfdng 1& do re cai phong len va doi khi la re thtf

cap d carot (Daucus carota), cd mot tang phdt sinh g6, chung tao thAnh mot It go thtf c&p , phan cdn lai la mo dir trit

- d re khoai lang (Ipomoca batatas) cd them mot tang phat sinh, chu yeu tao ra nhu mo lam re phong len nhif cu: cu khoai lang la mot ccf quan sinh san dinh difdng tao ra re d phia dildi

va than d phia tren

- 0 re cua cay cu cai dtfdng: la ket qua boat dong cua cac

tang phat sinh dong tarn Mdi tang phat sinh mdi tao ra mot vong sam cua nhu mo xen ke vdi vbng nhat cua mo dan truyen

4) Rd thich nghi de cung cap chat dinh dtfdng:

* Not (root nodude - hinh 14): d nhieu cay, dSc biet la

nhffng cay ho dau (Fabaceae) va nhtfng cay keo bong vang (ho Mimosaceae) co not rd Not re co chda vi khuan cd dinh dam, chung bien doi nitrogen tit khi quyen thanh hop chat nitro hffu

co de cay chu co the sd dung dUOc

l1''/Vr—not roHinh 14 - Re dau vdi cac not re

Vi du: vi khuan Rhizobium d rd cay dau hay Frankia d rd cay phi lao {Casuarina equiseti folia) hay cay Allocasuarina ,

chung di vao rd qua long rd, sif di vao nay kich thich td" bao

phan c^t nhanh chong, ket qud 14m cho rd phong len tao thanh not re, diftfc noi lien vdi mo dan truyen cua cay chu Cac te bao chtfa vo so' bacteriod, 14 nhu’ng te b4o vi khuan ditoc bien doi ben trong te b4o cua not re.

-Not rd co m4u hong la do sit hidn di^n cua mot loai protein van chuyen haemoglobin, ditqc tao ra trong te b4o chu de duy tri mot litqng oxi v4a du, trdnh 14m bat boat enzim nitrogenaz can thiet cho sit co dinh dam

* Ed San ho (coralloid root):

Di/qc tim thay d rd cua cac cay sdi (Quercus-Fagaceae), cay Alnus Betulaceae v4 thidn tue' (Cycas), Cacadaceae 14 do rd bi nhiem vi khuan Frankia v4 vi khuan lam Nostoc, tao th4nh mot kieu rd san ho, co d4c diem phan nhdnh litdng phan Cac

te b4o d mo phan sinh ngon khdng bi nhidm, trong khi nhu’ng

te b4o vd re bi nhu’ng sqi vi khuan v4 vi khuan lam xam nhap Te' b4o vung vd ph4t trid’n th4nh nhufng tui, trong do xay ra sit

cd dinh dam Nhu’ng te b4o vd ngo4i bi nhidm gdm chu bi v4 nhtfng te b4o chda tanin, trong khi nhtfng te b4o vd trong va

mo dan truyen khdng bi nhiem

* Ed chum (root cluster hay proteoid root):

Gdm mot nhdm cdc rd phu co long rd ben th4nh mot khdi d4y d4c trdn m4t dat nhtf mot so cay ho dau (Fabaceae) Do si/ sinh san, cd rat nhieu re con doc theo rd chinh Day 14 mot kid’u thich nghi d nhu’ng moi trifdng ngheo chat dinh dirdng, ben trong cdc rd con n4y mo xylem rat ph4t trien

*N&m rl (Mycorrhizae):

L4 mpt kid°u cpng sinh gitfa re v4 nam Sit cpng sinh n4y giup rd hap thu ditqc c4c chat dinh dtfdrng d4c bi^t 14 d cdc lo4i lan ki sinh v4 c4c cay thach nam (Erica)

Cd 2 loai nam rd:

+ Nam ngoai: (ectomycorrhizae) tao ra cdc khoi co hinh soi hay khuan ty the tren be mSt va daoc goi la bao nam (fungal sheath) 1& mot vung re (rhizosphere) 1& mot phan d ben trong re Khi khuan ty the xam nhap vao vung vd, nam moc gitfa nhiJng te bao tao ra mang Hartig (Hartig net) Nam chi d rong vung vd, va khdng xam nhap vao noi bi Rd bi nhiem ngSn v4 thifdng phan nhdnh Itfdng phan

+ Nam rd trong (endomycorrhizae), dSc biet d lan, mang

sinh chat cua te bao chu bao quanh sqi nam, tao ra nhtfng vdng xoan cua sqi nam d ben trong te bao

II- THAN

Cay song trong moi tnTdng khac nhau than cung cd cac bien doi hinh thdi de thich nghi va ton tai

1) Than song trong dat (undergound stem):

Khdng phai tat ca than deu khi sinh, cd nhieu loai than song trong dat hay than ngam thifdng cd dang rd, di/qc goi la cSn hanh (rhizome), la va nhdnh khi sinh moc len td cdn hanh nay Cdn hanh g&p nhieu nhat d cdc loai than cd, cd chute nang sinh san dinh ditdng

Than ngam cung cd chute n&ng nhiX mot cd quan dif tru’ nhif:

- Khoai tay: la mot loai than cu, Id va choi chi la cac vay va chi moc trong mu a dinh difdng

- Gifng: phan dn dirqc la cdn hanh da nien, vdi nhieu mdt ngdn, day mang cdc la la nhilng vay nhd mdng

- Lay On (corn), hanh, tdi cung la mot kieu than ngam mang hoa va Id tren mdt dat va mang cdc re bat dinh ben du’di.Vao miia khdng thuan loi cay rui la va song cham bdng cdc cdn hanh nay